hai dear frnds

please clarify my following doubts

1)how can I update my material database of Caesar
2) can we give gap between guides in Caesar ? my friend is saying its not a good practice to give gap between guides ,if we are providing gap needs to provide friction coefiecent ?
3) why we are checking stress in cold modules and nozzle in hot modules ,how does it make changes in our output please explain
4) hanger design case is makin with operatio case or design case? is it true if we are taking hanger design for both cases( ie w+P1+T1+H and w+P2+T2+H)
5) how does frictional support work?is it practical with zero friction?

I'm waiting for your reply as soon as possible

thanks dear frnds

regards
arun

Seeing your questions it looks like you need help from a senior pipe stress engineer !

1. See CAESAR II manual.
2. Yes you can. Always keep in mind that you are modelling the reality. How much of a gap is there in reality? Is it worth putting all these gaps in the model? Is your model conservative or not if you use these gaps? Do a search on this forum and/or on eng-tips.com and you will find a lot of guidance on this issue.
3. Read the design codes you are using. Also read some literature about piping and pipe stress. John Breen has given a lot of literature tips here: http://www.eng-tips.com/viewthread.cfm?qid=189629&page=3
4. CAESAR II will take worst case for the hanger design. Remember that you always first define the installation case, and than the operational/design case for hanger design. As it is a design, which load case do you see fit to use, design or operational?
5. This is basic physics and FEA knowledge you must have before using CAESAR II. Let's say you have 0.3 friction coefficient and your vertical force on the support is 1000 N. If your horizontal force is <= 333 N, the pipe will not move, if it is > 333 N it will move.
If it is practical to use zero friction? That is an issue often discussed here and in other forums. Is it practical to have 0 friction? What are the differences in results of you use a high or low friction coefficient? Ask yourself these questions and you will, hopefully, find your answers. Also do a bit of searching on this and other forums.

1)how can I update my material database of Caesar
From the Main Menu, select "\tools\Material Database Editor".

2) can we give gap between guides in Caesar ? my friend is saying its not a good practice to give gap between guides ,if we are providing gap needs to provide friction coefiecent ?
Yes you can put a gap on your restraints - that is what the "gap" box is for. Gaps are used all the time, and yes you can define friction at these locations.


3) why we are checking stress in cold modules and nozzle in hot modules ,how does it make changes in our output please explain
The failure mechanism for piping is different then the over-load conditions on nozzles (which vary by equipment type). This is a really broad question, can you be more specific?


4) hanger design case is makin with operatio case or design case? is it true if we are taking hanger design for both cases( ie w+P1+T1+H and w+P2+T2+H)
The hangers must be designed for all conditions that the piping system can experience.

5) how does frictional support work?is it practical with zero friction?
You define a "mu" value at each restraint. The friction force acting at that restraint is determined and added to the load vector for that specific load case. Friction is explained in detail in Chapter 6 of the Technical Reference Manual.